Upload & Sell: Off
zhangyue, don't buy the 50APO, mine focuses past infinity as well (slight bit) other functions seem normal, other then the flare issue, but we'll see how that turns out when I get my lens back.
My 50Lux doesn't have the focus past infinity problem.. Also sebboh, even with the MTF chart dip (I have no idea how to read MTF data), if I look at his leaves photo, that's not normal. If I shoot a textured object wide open, there's a straight sharp line across the whole frame with no softness (or at least none like what the OP is getting).
Depending on the angle and focusing distance, sometimes the line has a slight bend to it. One would have to actually run the test a bunch of times at different angles n focal distances to find the difference, and I've never really bothered doing that.